Home Forums Hunting & Shooting Handguns Learned about S&W revolver light primer strikes today

The other day I had my M69 out to the range shooting some heavy 300gr cast loads. After a few cylinders full it started having light firing pin strikes on 2 or 3 out of every five rounds. Later that night I took the grips and sideplate off and everything looked normal until I discovered the strain screw (On the lower portion of the grip frame placing tension on the mainspring) was about one full turn off from tight. I tightened it down and then put a witness mark and a dab of nail polish on it.

Today's range session confirmed that was the problem, and there were no more issues. I just wanted to mention it in case anyone else has this issue develop.

Thanks.

I have had the same (?) problem with my S&W 432 PD, .32 H&R Mag. snub nose revolver not firing when attempting to shoot it.
Other's also trying to shoot it were only 'clicking' away on chambered rounds.

Except for one friend who declared "There's nothing wrong with that gun! Give it to me!" and he stepped forward and aggressively fired
off all the reloaded rounds in rapid succession AND with accuracy." Then he asked, "Want to sell it?

No one has shot it since and that was a few years ago - I'll have to get it out and check out your solution. It was about my favorite . . .

Nothing new there

That screw can just simply work loose and give you those issues - but I've also had a few owners who wanted to decrease the DA trigger pull and they loosened that screw to ease the pull... All of a sudden they got light strikes! WHO-da thunk it?? That hammer needs "X" amount of inertia to properly ignite a primer - and removing mainspring pressure is NOT the way to work a trigger... FWIW..

Gotta make sure the primers are seated firmly in the primer pocket, too. If the primer isn't seated firmly, the energy from the pin hitting the ptimer will be used to seat the primer, but it might not have enough reserve to ignite it.

Yours is a J-frame piece with a coil spring so needs a different solution.

Your J doesn't have a strain screw because, as Ed says, it uses a coil mainspring. You'll need either a coil spacer, a new spring, or a longer firing pin. All are easy 5 minute fixes and fairly common. Cylinder and Slide makes longer firing pins that are about $12 or so, Wolff spring kits are around $20 or so. I would choose the long firing pin myself.

To the OP, I've replaced many strain screws that the owners or would be gunsmiths cut down too far in search of a lighter DA pull. With a C&S extra length firing pin and careful shortening of the strain screw the M69s can be worked into a pretty nice action.

I had the same problem with my model 69. Got it about three months ago and had three misfires in the first 150 rounds. The strain screw was tight. Then I switched from Winchester to Federal primers and have put over 250 rounds through it since then without a misfire. I was feeling pretty good about things.

I hadn't fired it in the double action mode until this past weekend, then on the second round I fired that way danged if I didn't have a misfire. Just took the grips off and the strain screw was maybe a half turn off tight. I just snugged it up and will take it for a test this week. I hope that does it.

I have five other S&W revolvers and never had one shake loose before.

??

Back in the PPC days, gamers like me would shorten the strain screw on our target revolvers as part of an action job. The reason we shortened the screw instead of just loosening it was because a loosened strain screw tends to get looser over time as the gun is used. A shortened screw could still be snugged up tight. Sometimes a screw was shortened too much and misfires resulted. The cure for that was to take a spent primer, remove the anvil, use a flat end punch to tap the firing pin indent back down, slip the primer cup over the end of the strain screw and tighten it. It acted as a shim to increase the force of the hammer fall. I have used that method on other revolvers that misfired, even though their strain screws were tight and had not been shortened.

The second I have a misfire with any Smith, I replace all springs with OEM and move forward from there.

I like lots of spring and polished surface areas.

I don't GAF what brand of ammo I'm feeding it. It needs to go BANG in DA every time.




Clark

Bobby, Steelhead had suggested doing that to me but the primer wouldn't fit between the frame and the screw, but he didn't (I don't think) suggest to remove the anvil. I'll try that.

It does work. I had a 629 that I shot for years set up like that.




Dave

Just to clarify, the primer cup goes between the end of the strain screw and the spring. You do have to remove the anvil and smooth out the firing pin indent with some sort of flat punch. Another issue with S&W DA revolvers that can cause misfires is cylinder or yoke end shake. They both result in excessive headspace and soften the firing pin blow. Either can be repaired in about 10 minutes by somebody that knows what they are doing and has a few simple tools.

OK, just did it but after removing the anvil had the beat the primer flat so it would fit between the end of the screw and the spring. Took a little fiddling to get it centered, but it seems to make a really nice shim. The DA pull isn't as easy as it was, but I'm looking forward to the next trip to the range.

IIRC the 432 uses a coil spring, so there is no strain screw.

If you're going to reduce mainspring pressure via the strain screw, the way to do it is by filing little bits off the end of the strain screw, rather than backing it out. That way when you re-install you can tighten it down fully. But one better know what they're about before removing metal from the strain screw, else you'll find yourself ordering a new strain screw from S&W. I personally find this preferable to a wolf spring since the mainsprings that S&W puts in their revolvers is much higher quality than anything you'll get from Wolf. Old timers used to thin the sides of the strain screw (you can read about Skeeter & Jordan recommending it), but this seriously weakens the mainspring (which it's supposed to), but does so to the point where that mainspring WILL break at some point. It's not hard to tune the mainspring for smooth DA if you have patience.

If the only thing you have done is add a spring kit, I doubt you'll ever have a problem.

No chit??

I was referring to a few 'owners' who tried to just loosen the screw a bit....

I know...that wasn't for your benefit, but for the benefit of others. I was confident you knew that.

My 6" and 8 3/8" 629's stayed put, but I had a 4" that would back the screw out after a few good range sessions.
Cranked down, Loctited, stayed put.

Some folks I guess think backing the screw off is a "trigger job".
Forgivable I reckon, if they stay away from stones, files and Dremels.

Backing the screw out is not the same as shortening it.
Personally, since I shoot my N frames SA only, a radius of trigger and they're good enough for me. No mainspring changes.
Dunno if y 4" got rebound slide spring change or not. Was a long time ago.